Pregnancy hormones refer to a group of hormones that are produced by the body during pregnancy. These hormones play an important role in preparing the mother's body for childbirth and helping the baby develop properly inside the womb. Some common pregnancy hormones include human chorionic gonadotropin (hCG), progesterone, estrogen, relaxin, and oxytocin. These hormones help to maintain the pregnancy, regulate the mother's metabolism, prevent uterine contractions that could lead to premature labor, and prepare the body for breastfeeding after the baby is born.